Respiratory Tract Oncobiome in Lung Carcinogenesis: Where Are We Now?

The importance of microbiota in developing and treating diseases, including lung cancer (LC), is becoming increasingly recognized. Studies have shown differences in microorganism populations in the upper and lower respiratory tracts of patients with lung cancer compared to healthy individuals, indicating a link between dysbiosis and lung cancer. However, it is not only important to identify "which bacteria are present" but also to understand "how" they affect lung carcinogenesis. The interactions between the host and lung microbiota are complex, and our knowledge of this relationship is limited. This review presents research findings on the bacterial lung microbiota and discusses the mechanisms by which lung-dwelling microorganisms may directly or indirectly contribute to the development of lung cancer. These mechanisms include influences on the host immune system regulation and the local immune microenvironment, the regulation of oncogenic signaling pathways in epithelial cells (causing cell cycle disorders, mutagenesis, and DNA damage), and lastly, the MAMPs-mediated path involving the effects of bacteriocins, TLRs signaling induction, and TNF release. A better understanding of lung microbiota's role in lung tumor pathology could lead to identifying new diagnostic and therapeutic biomarkers and developing personalized therapeutic management for lung cancer patients.

The Comparison of Serum Exosome Protein Profile in Diagnosis of NSCLC Patients.

A thorough study of the exosomal proteomic cargo may enable the identification of proteins that play an important role in cancer development. The aim of this study was to compare the protein profiles of the serum exosomes derived from non-small lung cancer (NSCLC) patients and healthy volunteers (control) using the high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) method to identify potentially new diagnostic and/or prognostic protein biomarkers. Proteins exclusively identified in NSCLC and control groups were analyzed using several bioinformatic tools and platforms (FunRich, Vesiclepedia, STRING, and TIMER2.0) to find key protein hubs involved in NSCLC progression and the acquisition of metastatic potential. This analysis revealed 150 NSCLC proteins, which are significantly involved in osmoregulation, cell-cell adhesion, cell motility, and differentiation. Among them, 3 proteins: Interleukin-34 (IL-34), HLA class II histocompatibility antigen, DM alpha chain (HLA-DMA), and HLA class II histocompatibility antigen, DO beta chain (HLA-DOB) were shown to be significantly involved in the cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) infiltration processes. Additionally, detected proteins were analyzed according to the presence of lymph node metastasis, showing that differences in frequency of detection of protein FAM166B, killer cell immunoglobulin-like receptor 2DL1, and olfactory receptor 52R1 correlate with the N feature according to the TNM Classification of Malignant Tumors. These results prove their involvement in NSCLC lymph node spread and metastasis. However, this study requires further investigation.

Panel of miR-150 and linc00673, regulators of CCR6/CCL20 may serve as non-invasive diagnostic marker of non-small cell lung cancer.

The C-C motif ligand 20 (CCL20) is a chemokine that specifically binds to the chemokine receptor 6 (CCR6) and the CCL20/CCR6 axis has been implicated in the non-small lung cancer (NSCLC) development and progression. Its expression is regulated by mutual interactions of non-coding RNAs (ncRNAs). This goals of presented study was to evaluate the expression level of CCR6/CCL20 mRNA in NSCLC tissue comparative to selected ncRNAs: miR-150, linc00673. The expression level of the studied ncRNAs was also assessed in serum extracellular vesicles (EVs). Thirty patients (n = 30) were enrolled as the study cohort. Total RNA was isolated from tumor tissue, adjacent macroscopically unchanged tissue and serum EVs. The expression level of studied genes and ncRNAs were estimated based on the qPCR method. Higher expression level of CCL20 mRNA but lower expression level of CCR6 mRNA were observed in tumor in comparison to control tissue. Relative to the smoking status, higher CCL20 (p < 0.05) and CCR6 mRNA (p > 0.05) expression levels were observed in current smokers than in never smokers. In serum EVs the expression level of miR-150 has a negative correlation with AJCC tumor staging, whereas the expression level of linc00673 positively correlated (p > 0.05). The lower expression level of miR-150 and higher expression level of linc00673 in serum EVs were observed in NSCLC patients with lymph nodes metastases (p > 0.05). Regarding the histopathological type, significantly lower expression level of miR-150 and higher expression level of linc00673 were observed in the serum EVs of patients with AC compared to patient with SCC. Our findings revealed that smoking significantly changed the expression level of CCL20 mRNA in NSCLC tissue. Changes in expression levels of miR-150 and linc00673 in the serum EVs of NSCLC patients in relation to presence of lymph node metastases and the stage of cancer development may serve as a non-invasive molecular biomarkers of tumor progression. Furthermore, expression levels of miR-150 and linc00673 may serve as non-intrusive diagnostic biomarkers differentiating adenocarcinoma from squamous cell carcinoma.

Analysis of the influence of selected protein markers as markers of nutritional status and inflammation on the occurrence of eventration after laparotomy.

<b><br>Introduction:</b> Eventration is a fairly rare complication after laparotomy, which consists of postoperative wound dehiscence and protrusion of the viscera outside the abdominal cavity. This complication is associated with a higher mortality rate. The known risk factors for this condition include malnutrition and the coexistence of inflammation or cancer.</br> <b><br>Aim:</b> The main aim of the study was to investigate the relationship between the occurrence of eventration after laparotomy and the patient's nutritional status with the intensity of inflammatory processes, expressed using selected protein markers.</br> <b><br>Material and method:</b> The study was based on the analysis of patients treated at our own center from January 2014 to December 2020. It included a group of patients who underwent laparotomy and who experienced eventration, as well as a control group of patients who underwent laparotomy but did not experience eventration after the procedure.</br> <b><br>Results:</b> The analysis showed that a lower serum albumin concentration is associated with a greater risk of eventration in patients who have undergone laparotomy due to acute abdominal disease. The study group and the control group differed significantly in the levels of: Hgb, serum total protein, CRP, lymphocytes, albumin, PCT, NRS.</br>.

Role of Beta-Carotene in Lung Cancer Primary Chemoprevention: A Systematic Review with Meta-Analysis and Meta-Regression.

Lung cancer is one of the most common neoplasms globally, with about 2.2 million new cases and 1.8 million deaths annually. Although the most important factor in reducing lung cancer risk is lifestyle change, most patients favour the use of supplements, for example, rather than quitting smoking or following a healthy diet. To better understand the efficacy of such interventions, a systematic review was performed of data from randomized controlled trials concerning the influence of beta-carotene supplementation on lung cancer risk in subjects with no lung cancer before the intervention. The search corpus comprised a number of databases and eight studies involving 167,141 participants, published by November 2021. The findings indicate that beta-carotene supplementation was associated with an increased risk of lung cancer (RR = 1.16, 95% CI = 1.06-1.26). This effect was even more noticeable among smokers and asbestos workers (RR = 1.21, 95% CI = 1.08-1.35) and non-medics (RR = 1.18, 95% CI = 1.07-1.29). A meta-regression found no relationship between the beta-carotene supplementation dose and the size of the negative effect associated with lung cancer risk. Our findings indicate that beta-carotene supplementation has no effect on lung cancer risk. Moreover, when used as the primary chemoprevention, beta-carotene may, in fact, increase the risk of lung cancer.

The Significance of the Alter miR let-7a and miR-335 Expression Level Regulating the CCR7/CCL19 Axis as Potential Biomarkers of Tumor Progression in NSCLC.

The chemokine receptor 7/C-C ligand 19 chemokine (CCR7/CCL19) has been implicated in the development and progression of NSCLC. Its expression is regulated by various epigenetic factors including miRNAs. The aim of this study was to assess the expression of CCR7/CCL19 in cancer tissue in relation to that of miRNAs (miR-let-7a, miR-335) as transcriptional regulators. The expression of the tested miRNAs was also evaluated in serum exosomes. Sixty patients (n = 60) were enrolled in the study. The total expression of the studied mRNA and miRNAs were evaluated using qPCR. Tumor tissue fragments, macroscopically unchanged adjacent tissue, and serum were used as controls. Higher CCR7 and CCL19 mRNA expression levels were observed in tumor tissue compared to control. According to stages of the disease (AJCC tumor staging), the greatest expression level of the studied genes' mRNA was observed in patients with stage III. In NSCLC patients, lower miR let-7a expression level was observed in tumor tissue compared to serum; however, miR-335 expression level was higher (p < 0.05). The expression level of miR-335 positively correlated with tumor size (T features according to pTNM staging) and AJCC tumor staging, while miR let-7a had a negative correlation (p > 0.05) with liquid biopsy. Significantly greater miR-335 expression level and lower miR let-7a expression level in serum were observed in patients with metastases to lymph nodes. Our findings reveal a significant correlation between the expression levels of the mRNA of the studied genes and miRNAs. Changes in miR-335 and miR let-7a expression levels in the serum exosomes of NSCLC patients in relation to lymph node metastases and tumor stage may serve as a non-invasive molecular biomarker of tumor progression.

Diagnostic value of PPARδ and miRNA-17 expression levels in patients with non-small cell lung cancer.

The PPARδ gene codes protein that belongs to the peroxisome proliferator-activated receptor (PPAR) family engaged in a variety of biological processes, including carcinogenesis. Specific biological and clinical roles of PPARδ in non-small cell lung cancer (NSCLC) is not fully explained. The association of PPARα with miRNA regulators (e.g. miRNA-17) has been documented, suggesting the existence of a functional relationship of all PPARs with epigenetic regulation. The aim of the study was to determine the PPARδ and miR-17 expression profiles in NSCLC and to assess their diagnostic value in lung carcinogenesis. PPARδ and miR-17 expressions was assessed by qPCR in NSCLC tissue samples (n = 26) and corresponding macroscopically unchanged lung tissue samples adjacent to the primary lesions served as control (n = 26). PPARδ and miR-17 expression were significantly lower in NSCLC than in the control (p = 0.0001 and p = 0.0178; respectively). A receiver operating characteristic (ROC) curve analysis demonstrated the diagnostic potential in discriminating NSCLC from the control with an area under the curve (AUC) of 0.914 for PPARδ and 0.692 for miR-17. Significant increase in PPARδ expression in the control for current smokers vs. former smokers (p = 0.0200) and increase in miR-17 expression in control tissue adjacent to adenocarcinoma subtype (p = 0.0422) were observed. Overexpression of miR-17 was observed at an early stage of lung carcinogenesis, which may suggest that it acts as a putative oncomiR. PPARδ and miR-17 may be markers differentiating tumour tissue from surgical margin and miR-17 may have diagnostic role in NSCLC histotypes differentiation.

Serum Extracellular Vesicle-Derived miRNAs in Patients with Non-Small Cell Lung Cancer-Search for Non-Invasive Diagnostic Biomarkers.

The aim of the study was a search for diagnostic and/or prognostic biomarkers in patients with non-small cell lung cancer (NSCLC) patients, based on circulating microRNAs (miRs: miR-23a, miR-361, miR-1228 and miR-let7i) in extracellular vesicles (EVs). Serum EVs were isolated from NSCLC patients (n = 31) and control subjects (n = 21). RNA was isolated from EVs and reverse transcription reaction was performed. Relative levels of miR-23a, miR-361, miR-1228 and miR-let7i were assessed in real-time qPCR using TaqMan probes. Analysis was based on the 2-ΔΔCT method. Statistically significant lower levels of miR-23a and miR-let7i were observed among NSCLC patients vs. control group: miR-23a, 0.054 vs. 0.107; miR-let7i, 0.193 vs. 0.369 (p = 0.003, p = 0.005, respectively). A receiver operating characteristic (ROC) curve analysis demonstrated the diagnostic potential of each individual serum EV-derived miRNA with an area under the curve AUC = 0.744 for miR-23a (p = 0.0003), 0.733 for miR-let7i (p = 0.0007). The decreased level of miR-23a in patients correlated with metastasis to lymph nodes and with AJCC tumor staging system. The results demonstrate that miR-23a and miR-let7i may prove clinically useful as significant, non-invasive markers in NSCLC diagnosis. Additionally, changing profile level of miR-23a that correlates with cancer development may be considered as an NSCLC progression marker.

Expression of inflammatory interleukins and selected miRNAs in non-small cell lung cancer.

Tumours are characterised by an ability to avoid immune destruction and the presence of cancer-associated inflammation. Better understanding of the link between lung cancer and such inflammation is vital for early detection and personalized treatment. Thus, we examined the mRNA expression of interleukins IL-1ß, IL-6, IL-17 and miR-9, miR-122 as potential useful biomarkers of NSCLC. Tumour tissues, non-cancerous tissue and blood samples were collected from 39 patients with primary NSCLC undergoing surgical treatment. The selected RNA was isolated from tissue samples and selected miRNAs from peripheral blood exosomes. This RNA was transcribed to cDNA and quantified using RT-qPCR. Significantly higher expression of the selected interleukins was observed in non-cancerous than tumour tissue, and IL-6 was significantly higher in the tumour tissue of patients with a history of ≤ 40 pack-years (PYs) (2.197, IQR: 0.821-4.415) than in those with > 40 PYs (0.461, IQR: 0.372-0.741; p = 0.037). It is clear that inflammatory processes play a role in NSCLC, as indicated by the upregulation of IL-1ß and IL-6 in tumour and adjacent tissue, and that smoking has a strong influence on inflammation in tumourigenesis, demonstrated by the upregulation of IL-6 in tumour samples among patients with ≤ 40 PYs compared to > 40 PYs.

Evaluation of the relationship between the IL-17A gene expression level and regulatory miRNA-9 in relation to tumor progression in patients with non-small cell lung cancer: a pilot study.

A pro-inflammatory cytokine, IL-17A, is associated with increased risk of developing numerous cancers, including non-small cell lung cancer (NSCLC). IL-17A is a target gene for miR-9. This encouraged us to analyze these two genes in terms of their usefulness as prognostic markers in NSCLC. The expression levels of IL-17A gene and miR-9 was assessed in 26 NSCLC tissue samples and 26 unchanged lung tissue adjacent to lung tumors (control tissue), using qPCR. In both tissue groups, a decreased expression of IL-17A was observed in 100% of samples. Increased expression of miRNA-9 was observed in 92% of tumor samples, and in 100% of control samples. Neither statistical differences in the level of expression IL-17A depending on the patient's age, gender, smoking status, nor histopathology of the cancer was found. Regarding the presence of nodule metastasis ('N' value in TNM classification), significantly lower expression level of IL-17A was observed in cN2 as compared with cN1 group. Additionally, statistically lower IL-17A expression was found in III versus II tumor stage (cAJCC classification). Significant negative correlation between both studied genes was revealed in SCC subgroup. This leads to the conclusion that miRNA-9 can regulate the expression of IL-17A as an IL-17A mRNA antagonistic mediator. Inhibition of proinflammatory action of IL-17A in correlation with tumor progression can be related to various activity of Th17 cells on cancer development according to its immunogenicity, and also may suggest suppressive role of IL-17A in tumor progression. However, because of low number of analyzed samples, further studies on the functional role of IL-17A in development and/or progression NSCLC seem warranted.

An assessment of the relationship between the expression of CCR7/CCL19 axis and selected regulatory miRNAs in non-small cell lung cancer.

CC chemokine receptor type 7 (CCR7) and its ligands has been implicated in the occurrence and progression of NSCLC. Previous studies have revealed that the diagnostic value of CCR7/CCL19 axis in lung tumorigenesis remains controversial. The present study evaluates the relationship between the mRNA expression of CCR7/CCL19 axis and selected regulatory miRNAs in NSCLC patients. It analyzes the expression level of CCR7 mRNA and its ligand in tumor tissue in relation to expression level of two miRNAs: miR let-7a and miR-335, as transcriptional regulators of study genes. Twenty-seven patients (n = 27) were enrolled. The expression of the studied genes and miRNAs was evaluated by qPCR. Tumour tissue fragments, adjacent macroscopically-unchanged lung tissue (control) and patient serum were used as biological material for study. Elevated expression of CCR7 and CCL19 mRNA was observed in patients with metastasis to lymph nodes. We noticed upregulated miR-335 expression and downregulated miR let-7a expression in patient serum with regard to AJCC tumor staging. Higher miR-335 expression and lower miR let-7a expression level was observed in patients with metastasis to lymph node. The presence of changes observed in the expression level of miR-335 and miR let-7a in the serum of NSCLC patients in relation to lymph node metastases and tumor stage may serve as a non-invasive molecular biomarker of tumor progression; however, this observation requires further investigation.

A Strong Decrease in TIMP3 Expression Mediated by the Presence of miR-17 and 20a Enables Extracellular Matrix Remodeling in the NSCLC Lesion Surroundings.

Background: Lung cancer is one of the most common causes of death worldwide with a relatively high fatality rate and a mean 5-years survival of about 18%. One of the hallmarks of cancer is the extracellular matrix (ECM) remodeling, which is crucial for metastasis. This process may be regulated by miRs targeting metalloproteinases (MMPs) associated with the ECM breakdown and metastatic process or blocking the action of tissue inhibitors of metalloproteinases (TIMPs). Search for early biomarkers is essential in detecting non-small cell lung cancer (NSCLC) and distinguishing its subtypes: Adenocarcinoma (AC) from Squamous Cell Carcinoma (SCC), enabling targeted chemotherapy. Methods: MiR-17 and miR-20a targeting MMP2 and TIMP3 were selected by TCGA data analysis with further validation using miRTarBase and literature. The study group comprised 47 patients with primary NSCLC (AC and SCC subtypes). RNA was isolated from the tumor and normal-looking neighboring tissue (NLNT) free of cancer cells. MiRs from peripheral blood exosomes were extracted on admission and 5-7 days after surgery. Gene and miRs expression were assessed in qPCR using TaqMan probes. Results: The MMP2 has been expressed on a similar level in NLNT, as in cancer. While, TIMP3 expression was decreased both in cancer tissue and NLNT, with significantly lower expression in cancer. TIMP3 downregulation in NLNT and in SCC subtype correlated negatively with miR-20a. The preoperative miR-17 expression was significantly higher among patients with SCC compared to AC. Receiver operating characteristic (ROC) analysis of miR-17 as AC subtype classifier revealed 90% specificity and 48% sensitivity in optimal cut-off point with area under ROC curve (AUC): 0.71 (95%CI: 0.55-0.87). Within NSCLC subtypes: a strong negative correlation between pack-years (PY) and TIMP3 expression was observed for NLNT in the SCC group. Conclusion: The TIMP3 silencing observed in the NLNT and its negative correlation with presurgical expression of miR-20a (from serum exosomes), suggest that miRs can influence ECM remodeling at a distance from the center of the lesion. The miRs expression pattern in serum obtained before surgery significantly differs between AC and SCC subtypes. Moreover, decreased TIMP3 expression in NLNT (in SCC group) negatively correlates with the amount of tobacco smoked in a lifetime in PY.

Intratumor heterogeneity and tissue distribution of KRAS mutation in non-small cell lung cancer: implications for detection of mutated KRAS oncogene in exhaled breath condensate.

PURPOSE: Mutated KRAS oncogene in exhaled breath condensate (EBC) can be a genetic marker of non-small cell lung cancer (NSCLC). However, a possibility of inhomogeneous distribution in cancer tissue and intratumor heterogeneity of KRAS mutation may decrease its significance. We investigated a status of KRAS point mutation and its sequence at codon 12 in 51 NSCLC patients after tumor resection. The comparison of KRAS mutation status between EBC-DNA and cancer tissue was performed in 19 cases. METHODS: Five cancer tissue samples from disparate tumor regions and one from normal lung were harvested at surgery. EBC was collected for DNA analysis the previous day. KRAS point mutations at codon 12 were detected using mutant-enriched PCR technique and pyrosequenced. RESULTS: Forty-six cancers revealed concordance of KRAS mutation status: 27 contained mutated KRAS and 19 had only wild KRAS. Five NSCLCs revealed inhomogeneous distribution of KRAS mutation. Two different mutations were found in 14 NSCLCs and the most frequent one was G12D and G12V (n = 8). No mutated KRAS was found in normal lung. The concordance ratios of KRAS sequence in codon 12 between EBC-DNA and cancer were 18/19 for NSCLC patients and 11/12 for KRAS mutation positive NSCLC. CONCLUSIONS: Intratumor heterogeneity and inhomogeneous distribution of KRAS point mutation in codon 12 in cancer tissue can occur in NSCLCs. There was a high accordance between KRAS mutation status in EBC-DNA and cancer tissue in NSCLC patients what suggests usefulness of monitoring KRAS mutation in EBC-DNA as a biomarker of NSCLC.

The Expression Levels of IL-4/IL-13/STAT6 Signaling Pathway Genes and SOCS3 Could Help to Differentiate the Histopathological Subtypes of Non-Small Cell Lung Carcinoma.

BACKGROUND: The interleukin (IL)-4/IL-13/signal transducer and activator of transcription (STAT) 6 signaling pathway and the SOCS3 gene, one of its main regulators, constitute an important link between the inflammation process in the epithelial cells and inflammatory-related tumorigenesis. The present study is the first to evaluate IL-4, IL-13, STAT6, and SOCS3 mRNA expression in non-small cell lung carcinoma (NSCLC) histopathological subtypes. METHODS: Gene expression levels were assessed using TaqMan® probes by quantitative reverse transcription PCR (qRT-PCR) in lung tumor samples and unchanged lung tissue samples. RESULTS: Increased expression of IL-4, IL-13, and STAT6 was observed in all histopathological NSCLC subtypes (squamous cell carcinoma [SCC], adenocarcinoma [AC], and large cell carcinoma [LCC]). Significantly higher expression of IL-13 and STAT6 (p = 0.019 and p = 0.008, respectively) was found in SCC than in LCC. No statistically significant differences were found for IL-4. Significantly higher SOCS3 expression was found in LCC than in AC (p = 0.027). A negative correlation (rho = -0.519) was observed for the STAT6 and SOCS3 genes in SCC (p = 0.005). No associations were found between gene expression and tumor staging (post-operative Tumor Node Metastasis [pTNM], American Joint Committee on Cancer [AJCC]), patients' age, sex, or history of smoking. CONCLUSIONS: As the number of LCC cases in our study was quite low, the statistically significant results obtained should be confirmed in a larger group of patients, particularly as the relationships identified between increased IL-4, IL-13, and STAT6 mRNA expression and decreased SOCS3 expression suggest that these genes may serve as potential diagnostic markers for differentiating between NSCLC histopathological subtypes.

Outcome of pleurodesis using different agents in management prolonged air leakage following lung resection.

BACKGROUND AND AIMS: Prolonged air leaks (PAL) are a common problem after pulmonary resection. PAL can be a source of significant complications. One of the treatment options is chemical pleurodesis. MATERIAL AND METHODS: The efficiency of three methods of treatment of PAL after lung resection was evaluated. In Iodine_ group aqueous iodine solution (lat.Tinctura Jodi) was applied intrapleurally (30 patients); in Doxycycline_group (34 patients) 200 mg of Doxycyclin was given and in Drainage_group 35 patients were applied Lidocaine solution only. RESULTS: The group investigated was similar with regard to age [F = 0.04, P = 0.96] and the amount of air leakage (approx. 462 mL/min). The shortest drainage time and hospital stay was observed in the Iodine_group [10.57, P < 0.001]. However, this therapy was connected with strongly perceptible chest pain (P < 0.0001]). The number of case of pneumothorax recurrence was low and it was the same was seen in other methods of treatment [F = 0.87, P = 0.42]. Allergic reactions were not observed. The number of episodes of tachycardia, hypotension, dyspnea, pneumonia, subcutaneus empyema, fluid collection, emphysema, pneumothorax recurrence and number of re-thoracotomies were statistically similar in all three methods of treatment. CONCLUSION: Iodine pleurodesis can be considered as one of possible treatment methods of PAL after lung resection as it showed favorable results compared with Doxycycline pleurodesis or drainage alone regarding duration of air leakage, hospitalization and pneumothorax recurrence with only slightly increased pleural pain.

Immunoexpression analysis of selected JAK/STAT pathway molecules in patients with non- small-cell lung cancer.

INTRODUCTION    Signal transducer and activator of transcription (STAT) proteins are critically involved in tumorigenesis in various cancers, including lung cancer. OBJECTIVES    The aim of the study was to analyze the immunoexpression levels of 3 STAT proteins: STAT3, STAT5, and STAT6 in their phosphorylated forms (pSTATs), STAT inhibitors PIAS3 and SOCS3, and additionally cyclooxygenase 2 (COX­2), as potential diagnostic and prognostic markers in lung cancer. PATIENTS AND METHODS    The study included 71 patients diagnosed with non- small-cell lung cancer (NSCLC). The immunoexpression levels of the proteins were assessed in lung tissue samples, using an enzyme­linked immunosorbent assay. Tumors were staged using the postoperative TNM classification. RESULTS    All studied STATs were overexpressed in 54% to 55% of NSCLC specimens. Significantly higher STAT3 and STAT6 immunoexpression levels were observed in squamous cell carcinoma. Significant differences between NSCLC samples and controls were found for STAT5. Significantly higher STAT5 levels were observed in pT2 tumors. The COX­2 overexpression was observed in 55% of NSCLC specimens and was significantly higher in T2 tumors. STAT inhibitors were underexpressed in 56% to 58% of NSCLC specimens. The PIAS3 immunoexpression was significantly lower in non-squamous cell carcinoma. The SOCS3 level was significantly lower in smaller tumors (pT1). Negative correlations between STAT5 and PIAS3 levels, as well as between STAT6 and SOCS levels, and a positive correlation between STAT5 and COX-2 levels were observed. CONCLUSIONS    The deregulated expression of the studied pSTATs and their inhibitors may be involved in the development and progression of lung cancer. The observed differences between the histotypes suggest the potential usefulness of STAT proteins as diagnostic markers. Our results may contribute to the search for targets in lung cancer therapy.

Small suitability of the DLEC1, MLH1 and TUSC4 mRNA expression analysis as potential prognostic or differentiating markers for NSCLC patients in the Polish population.

According to the latest data, lung cancer is one of the most common cancer worldwide, men contributing nearly 21.2% and women 8.6% of all diagnosed cancers. Late detection of tumour drastically reduces the chance for a cure. Thus, it is important to search for candidate biomarkers for screening of early stage nonsmall cell lung carcinoma (NSCLC). Tumour suppressor genes, DLEC1, TUSC4 and MLH1, localized on 3p21 are recognized to play a role in NSCLC carcinogenesis. The aim of this study was to assess the relationship between the DLEC1, TUSC4 and MLH1 mRNA expression, and clinical features of NSCLC patients, tobacco addiction, and tumour histopathological characteristics. The DLEC1, TUSC4 and MLH1 expression was analysed in lung tumour tissue samples obtained from 69 patients diagnosed with NSCLC: squamous cell carcinoma (n = 34), adenocarcinoma (n = 24), large cell carcinoma (n = 5), carcinoma adenosquamosum (n = 5). A decreased gene expression (RQ < 0.7) was observed for DLEC1 in 60.9% of tumour samples, for MLH1 in 50.7% and for TUSC4 in 26% of NSCLC samples. DLEC1 was decreased in more aggressive subtypes: large cell carcinoma and adenocarcinoma-squamous cell carcinoma. The simultaneous downregulation of two of the studied genes, DLEC1 andMLH1,was observed in 30.4% of NSCLCsamples, highlighting the importance of these two genes in lung carcinogenesis. We found no correlation between the DLEC1, TUSC4 and MLH1 gene expression and NSCLC patient characteristics (gender, age and smoking) or cancer histopathology. No significant differences in the gene expression among NSCLC subtypes indicate the weakness of DLEC1, TUSC4 and MLH1 expression analysis as potential differentiating markers of NSCLC subtypes in the Polish population.

FHIT promoter methylation status, low protein and high mRNA levels in patients with non-small cell lung cancer.

FHIT is a tumor suppressor gene that is frequently silenced in non-small cell lung cancer (NSCLC) and also in preneoplastic lesions. Promoter hypermethylation was previously observed in NSCLC, and its epigenetic silencing, observed on mRNA or protein level, was proposed to predict NSCLC outcome. In the present study we evaluated the relationship between FHIT expression on mRNA level and promoter methylation, or immunoexpression level. The aim of this study was to analyze the usefulness of FHIT as early differentiating biomarker in NSCLC patients. Lung tissue specimens were obtained from 59 patients with diagnosed NSCLC (SCC=34, AC=20, LCC=5). FHIT promoter methylation was assessed in methylation-specific PCR. Relative expression analysis of FHIT was performed in real-time PCR (qPCR) and protein immunoexpression by ELISA assay. Significant differences in FHIT expression between NSCLC histopathological groups (SCC, AC, LCC) were observed (p=0.000009), with the lowest level in SCC. FHIT expression was significantly higher (p=0.034) in men vs. women. Methylated FHIT alleles were present both in NSCLC and control specimens. Mean MI value was higher in control tissue vs. neoplasm, and in men vs. women and it increased with patient age. Significant increase in MI level was observed in N0 group vs. N1 and N2, according to the TNM staging (p=0.0073). Differences in FHIT expression levels between AC, LCC and SCC indicated the usefulness of this gene as a diagnostic marker for NSCLC subtype differentiation. FHIT promoter hypermethylation both in cancer and control tissue indicated the presence of epigenetic alterations in early stage of NSCLC development. Differences in gene promoter methylation between cancer patients with and without node infiltration might be considered as a prognostic marker. Significantly lower FHIT protein immunoexpression was revealed in the group with long and intense history of smoking assessed as PYs (PY<40 vs. PY≥40, p=0.01). These results suggest the need of further study on FHIT as a potential biomarker.

Expression level and methylation status of three tumor suppressor genes, DLEC1, ITGA9 and MLH1, in non-small cell lung cancer.

Despite therapeutic advances, lung cancer remains one of the most common causes of cancer-related death in the world. There is a need to develop biomarkers of diagnostic and/or prognostic value and to translate findings in basic science research to clinical application. Tumor suppressor genes (TSGs) represent potential useful markers for disease detection, progression and treatment target. We tried to elucidate the role of three 3p21.3 TSGs: DLEC1, ITGA9 and MLH1, in non-small cell lung cancer (NSCLC). We assessed their expression pattern by qPCR in 59 NSCLC tissues and in the matched macroscopically unchanged lung tissues. Additionally, we analyzed gene promoter methylation status by methylation-specific PCR in NSCLC samples. We did not find significant correlations between gene expression and methylation. In case of DLEC1 and ITGA9, expression levels were decreased in 71-78 % of tumor samples and significantly different between tumor and normal tissues (P = 0.0001). It could point to their diagnostic value. ITGA9 could also be regarded as a diagnostic marker differentiating NSCLC subtypes, as its expression level was significantly lower in squamous cell carcinoma (P = 0.001). The simultaneous down-regulation of DLEC1 and ITGA9 was observed in 52.5 % of NSCLCs. MSPs revealed high frequencies of gene promoter methylation in NSCLCs: 84 % for DLEC1 and MLH1 and 57 % for ITGA9. Methylation indexes reflected moderate gene methylation levels: 34 % for ITGA9, 27 % for MLH1 and 26 % for DLEC1. However, frequent simultaneous methylation of the studied genes in more than 50 % of NSCLCs suggests the possibility of consider them as a panel of epigenetic markers.

Quantitative analysis of mRNA expression levels and DNA methylation profiles of three neighboring genes: FUS1, NPRL2/G21 and RASSF1A in non-small cell lung cancer patients.

BACKGROUND: Tumor suppressor gene (TSG) inactivation plays a crucial role in carcinogenesis. FUS1, NPRL2/G21 and RASSF1A are TSGs from LUCA region at 3p21.3, a critical chromosomal region in lung cancer development. The aim of the study was to analyze and compare the expression levels of these 3 TSGs in NSCLC, as well as in macroscopically unchanged lung tissue surrounding the primary lesion, and to look for the possible epigenetic mechanism of TSG inactivation via gene promoter methylation. METHODS: Expression levels of 3 TSGs and 2 DNA methyltransferases, DNMT1 and DNMT3B, were assessed using real-time PCR method (qPCR) in 59 primary non-small cell lung tumors and the matched macroscopically unchanged lung tissue samples. Promoter methylation status of TSGs was analyzed using methylation-specific PCRs (MSP method) and Methylation Index (MI) value was calculated for each gene. RESULTS: The expression of all three TSGs were significantly different between NSCLC subtypes: RASSF1A and FUS1 expression levels were significantly lower in squamous cell carcinoma (SCC), and NPRL2/G21 in adenocarcinoma (AC). RASSF1A showed significantly lower expression in tumors vs macroscopically unchanged lung tissues. Methylation frequency was 38-76%, depending on the gene. The highest MI value was found for RASSF1A (52%) and the lowest for NPRL2/G21 (5%). The simultaneous decreased expression and methylation of at least one RASSF1A allele was observed in 71% tumor samples. Inverse correlation between gene expression and promoter methylation was found for FUS1 (rs = -0.41) in SCC subtype. Expression levels of DNMTs were significantly increased in 75-92% NSCLCs and were significantly higher in tumors than in normal lung tissue. However, no correlation between mRNA expression levels of DNMTs and DNA methylation status of the studied TSGs was found. CONCLUSIONS: The results indicate the potential role of the studied TSGs in the differentiation of NSCLC histopathological subtypes. The significant differences in RASSF1A expression levels between NSCLC and macroscopically unchanged lung tissue highlight its possible diagnostic role in lung cancer in situ recognition. High percentage of lung tumor samples with simultaneous RASSF1A decreased expression and gene promoter methylation indicates its epigenetic silencing. However, DNMT overexpression doesn't seem to be a critical determinate of its promoter hypermethylation.