Prognostic value of cell-cycle regulators and cellular biomarkers in laryngeal squamous cell carcinoma

p16 Expression in Laryngeal Squamous Cell Carcinoma: A Surrogate or Independent Prognostic Marker?

Laryngeal squamous cell carcinoma (LSCC) is a common malignancy that, despite scientific advancements, has not seen an improvement in its prognosis in the last decades. Few promising predictive markers have been found and none are relevant in clinical practice. p16ink4a, an oncosuppressor protein involved in cell cycle arrest, with a prognostic impact on other cancers, has been widely used in the head and neck region as a surrogate marker of HPV infection. Published papers and recent meta-analyses seem to minimize the biological role of HPV in the context of LSCC's cancerogenesis, and to disprove the reliability of p16ink4a as a surrogate prognostic marker in this context, while still highlighting its potential role as an independent predictor of survival. Unfortunately, the available literature, in particular during the last two decades, is often not focused on its potential role as an independent biomarker and few relevant data are found in papers mainly focused on HPV. The available data suggest that future research should focus specifically on p16ink4a, taking into account both its potential inactivation and overexpression, different patterns of staining, and immunohistochemistry cutoffs, and should focus not on its potential role as a surrogate marker but on its independent role as a predictor of survival.

Methylation of CDKN2B CpG islands is associated with upregulated telomerase activity in children with acute lymphoblastic leukemia

The aim of the present study was to investigate the association between methylation of cyclin-dependent kinase inhibitor 2B (CDKN2B) CpG islands and telomerase activity in children with acute lymphoblastic leukemia (ALL). A total of 72 children with ALL and 12 children with immune thrombocytopenia (ITP) were subjected to bone marrow aspiration and methylation-specific polymerase chain reaction analysis, and modified telomeric repeat amplification protocol assay analyses, to evaluate CDKN2B methylation and telomerase activity, respectively. The results of the present study demonstrated that, of these 72 children with ALL, 31 exhibited CDKN2B methylation at diagnosis (43.1%), whereas 41 exhibited no CDKN2B methylation (36.9%). However, no CDKN2B methylation was detected in the ITP controls. Furthermore, the mean level of telomerase activity was 39.52±39.33 total product generated (TPG) units in children with ALL, which was significantly increased compared with 2.49±2.27 TPG units in the ITP controls (P=0.002). The mean levels of telomerase were 49.09±44.43 and 29.99±32.43 TPG units in children with ALL with and without CDKN2B methylation, respectively (P=0.041), therefore children with ALL exhibited significantly increased levels of telomerase. The increased telomerase activity was significantly associated with increased risk of childhood ALL (P=0.023). A total of 22/31 children with ALL with methylated CDKN2B (71.0%) and 17/41 children with ALL with unmethylated CDKN2B (41.46%) exhibited increased telomerase activity (>15 TPG units). The results of the present study suggest that hypermethylation of CDKN2B CpG islands and hyperactivity of telomerase are common events in childhood ALL, and hypermethylation of CDKN2B CpG islands was significantly associated with upregulated telomerase activity (P=0.013).

Low mRNA expression levels of kallikrein-related peptidase 4 (KLK4) predict short-term relapse in patients with laryngeal squamous cell carcinoma

Several members of the family of tissue kallikrein and kallikrein-related peptidases have been suggested as promising tumor biomarkers with important prognostic significance. However, only one (KLK11) has already been studied in laryngeal squamous cell carcinoma (LSCC) as a potential biomarker for LSCC diagnosis and/or prognosis. Our study investigated the prognostic value of kallikrein-related peptidase-4 (KLK4) mRNA expression as a molecular tissue biomarker in LSCC. For this purpose, KLK4 mRNA expression analysis was performed in 116 cancerous and 74 paired non-cancerous laryngeal tissue specimens obtained from patients that had undergone surgical treatment for primary LSCC. A remarkable downregulation of KLK4 mRNA expression was discovered in laryngeal tumors, compared to non-cancerous laryngeal tissue specimens. KLK4 mRNA expression was also shown to distinguish LSCC from non-cancerous laryngeal tissues. Furthermore, low KLK4 mRNA expression was shown to predict poor disease-free survival, independently of the histological grade and size of the malignant tumor as well as patient TNM stage. According to Kaplan-Meier survival analysis, low KLK4 mRNA expression predicts short-term relapse even among patients with well-differentiated tumors or those at an early TNM stage. Thus, KLK4 mRNA positivity could be regarded as a novel independent indicator of favorable prognosis for the disease-free survival of LSCC patients.

The expression of TLR pathway molecules in peripheral blood mononuclear cells and their relationship with tumor invasion and cytokine secretion in laryngeal carcinoma

PURPOSE

The aim of this study was to analyze of TLRs mRNA expression in peripheral blood mononuclear cells as potential biomarkers of neoplastic lesions progress and to evaluate their role in the possible mechanisms responsible for the secretion of cytokines in laryngeal cancer.

MATERIAL/METHODS

The analysis of TLR2, TLR4, TRAF6, IRAK1 expression in isolated PBMCs by the reverse transcription PCR (RT-PCR) analysis as well as IL-6, IL-8 and TNF-α levels in supernatants of peripheral blood mononuclear cells from 55 patients with carcinoma of the larynx was performed by ELISA. The invasiveness of carcinoma was evaluated according to tumor front grading, TFG.

RESULTS

We noted that tumors with a well-defined borderline were characterized by significantly higher values of the average expression of TRAF6. Our research also confirmed that more aggressive carcinomas according to TFG, with a more dispersed type of invasion were characterized by significantly lower values of the average expression of IRAK1. Moreover, we observed that tumors with the invasion of cartilage were characterized by significantly lower values of the average expression of TLR4. In addition, the relationships of TLR2 with IL-6 and TNF-α level were highlighted. Significant interconnections were also found between the TLR4 and IL-8, TNF-α, IL-6 secretion after stimulation. The relationships of TRAF6 with IL-8 production after stimulation were noted.

CONCLUSIONS

Our findings confirmed the implication of the TLRs pathway molecules in proinflammatory cytokine secretions and their importance as encouraging potential indicators for assessment of the degree of aggressive tumor phenotype.