Background: The latest immunotherapy, used in the treatment of non-small cell lung cancer (NSCLC), uses monoclonal antibodies directed against programmed death ligand 1 (PD-L1) to inhibit its interaction with the PD-1 receptor. Elevated levels of PD-L1 expression were observed on NSCLC cells. The association between PD-L1 expression and clinicopathological features is still unclear. Therefore, we examined this relationship and also compare PD-L1 expression levels with Ki-67, p63 and TTF-1. Methods: 866 samples of NSCLCs were used to prepare tissue microarrays (TMAs) on which immunohistochemical (IHC) reactions were performed. Changes in the level of CD274 (PD-L1) gene expression in 62 NSCLC tumors were tested in relation to 14 normal lung tissues by real-time PCR reactions (RT-PCR). Results: PD-L1 expression was observed in 32.6% of NSCLCs. PD-L1 expression was increased in higher malignancy grades (G) (p < 0.0001) and in higher lymph node status (pN) (p = 0.0428). The patients with low PD-L1 expression had longer overall survival compared to the group with high expression (p = 0.0332) in adenocarcinoma (AC) only. Conclusions: PD-L1 expression seems to be associated with increased tumor proliferation and aggressiveness as well as shorter patient survival in NSCLC, predominantly in the AC group.

Background: Recent in vitro studies have indicated that irisin inhibits proliferation, migration and epithelial-mesenchymal transition. Irisin expression has not been studied in tumour tissues of non-small cell lung cancer (NSCLC) patients yet. The aim of the study was to determine the irisin expression in NSCLCs in comparison to the clinicopathological factors and expression of TTF-1, p63 and Ki-67. Material and methods: Tissue microarrays with 729 NSCLC and 140 non-malignant lung tissue (NMLT) were used to perform immunohistochemical reactions. Laser Capture Microdissection (LCM) was used to collect cancer and stromal cells from NSCLCs. FNDC5 expression was tested for LCM samples, 75 NSCLCs and 25 NMLTs with the RT-PCR technique. Western-blot, immunofluorescence reaction and RT-PCR assays were performed on lung cancer cell lines. Results: Irisin expression was observed in NSCLC cancer cells and stromal fibroblasts. In cancer cells, irisin expression was decreased in higher grades (G) of malignancy, tumour size (T) and according to lymph node metastasis. In stromal cells, irisin expression was increased in higher G and advanced T. A shorter overall survival was observed in patients with higher irisin expression in NSCLC stromal cells. Conclusions: Irisin expression in stromal fibroblasts may influence cancer cell proliferation and may be a prognostic factor for survival in NSCLC.

There is a necessity in finding biomarkers, which would predict the risk level of malignant transformation. Our study has confirmed that altered expressions of the p16 and p27 proteins might be useful biomarkers in the progression of laryngeal squamous cell carcinomas (LSCC).

Human papillomavirus (HPV) belongs to the Papillomaviridae family and infects squamous cells and mucous membranes of humans. Various studies conducted over the last years have shown a correlation between HPV infection and carcinogenesis process. The DNA of the virus is detected in approximately 20% of cancers of the upper respiratory tract. The presence of HPV in cancerous lesion of the larynx varies depending on the procedure applied for sample collection and the viral DNA detection method. The high variance in the frequency of HPV detection is observed even among results obtained with the use of PCR reaction. It varies between 3 and 85%. HPV is also the etiological factor of laryngeal papillomas in both children and adults. However, a considerable amount of research demonstrates that 1-7% of the larynx papillomas in adults undergo transformation into squamous cell carcinoma. The aim of the study was to summarize the current state of knowledge regarding the presence of the HPV virus in the larynx as well as its participation in malignant transformation.

Background/Aim: The minichromosome maintenance proteins (MCMs) may be potential biomarkers of cancer cell proliferation. They are essential to initiate DNA replication. The aim of the study was to investigate the level of MCM5 expression in benign lesions (BLs) and laryngeal squamous cell cancer (LSCC). Materials and Methods: Immunohistochemical (IHC) analysis was carried out on 83 LSCCs and 10 BLs. Western-blot, immunofluorescence analysis (IF) and real-time PCR (RT-PCR) were performed using HEp-2 cancer cells and HaCaT keratinocytes. Results: The expression of MCM5 was higher in LSCC than in the BLs (p<0.0001) and was higher in subsequent malignancies of LSCC. Positive correlations were demonstrated between the expression levels of MCM5 and the Ki-67 antigen. In vitro studies have confirmed that the expression of MCM5 is elevated in cancer cells. Conclusion: MCM5 protein may be used as a potential marker of cancer cell proliferation in LSCC.