Interleukin-6-Positive Immune Cells as a Possible New Immunologic Marker Associated With the Colorectal Cancer Prognosis.

Chronic inflammation creates tumor microenvironment (TME) that facilitates colorectal cancer (CRC) cell proliferation, migration, metastasis, and tumor progression. Interleukin-6 (IL-6) is a proinflammatory cytokine with a pleiotropic effect on CRC development. We aimed to evaluate IL-6 expression in tumor cells and in immune cells in TME, to assess the serum level and IL6 -174 G/C genotype distribution and to correlate the results with selected morphologic and clinical parameters that may add useful information in understanding the mechanisms of human CRC progression. A total of 153 patients with CRC were recruited in the current study. We assessed the IL-6 serum concentration through the ELISA method, the expression of IL-6 in tumor and in immune cells by immunohistochemical and double immunofluorescence staining, the MSI status by immunоhistochemistry for 4 mismatch repair (MMR) proteins, and the genotype distributions for IL6 -174G/C (rs1800795) single-nucleotide polymorphism through PCR-RFLP method. Our results showed that serum IL-6 level were increased in CRC patients as compared with healthy controls (P<0.0001), and in patients with cancers with advanced histologic type (type IV). However, the higher concentration (above the median of 55.71 pg/mL) was with borderline association with longer survival of the patients after surgical therapy (P=0.055, Log rank test). We also found that IL-6+ immune cells prevailed in the invasive front (IF) of tumors compared with the tumor stroma (TS) (P<0.0001). More IL-6+ cells were recruited in the tumors with less advanced histologic type (I+II), with stronger inflammatory infiltrate in the IF, in early pTNM stages (I+II), without lymph node and distant metastases and the higher levels of IL-6+ cells, especially in the IF, were associated with longer survival (P=0.012). The results of our study suggest that although the serum levels of IL-6 are higher in CRC, the increased IL-6+ cells in tumor microenvironment, both in the invasive front and in tumor stroma, as well as the higher serum levels are associated with good prognostic variables and longer survival of the patients mainly in the early stages of CRC.

Role of Elevated Serum TGF-ß1 and the Common Promoter TGFB1-509C/T Polymorphism in the Development and Progression of Primary Glial Tumors and Brain Metastases.

Background and Objectives: The role of transforming growth factor-beta1 (TGF-ß1) has been widely studied in the context of carcinogenesis. It has been involved in the pathogenesis of primary brain tumors or brain metastases due to its pleiotropic effects on immune regulation and tissue homeostasis. In line with recent findings, the aim of the current study was to examine the role of circulating TGF-ß1 and the -509C/T functional polymorphism (rs1800469) in the TGFB1 gene promoter in the susceptibility and progression of primary brain tumors and brain metastases among patients from the Bulgarian population. Materials and Methods: Cases with a confirmed diagnosis were genotyped by the polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP). Serum TGF-ß1 levels were determined by ELISA. Immunohistochemical evaluation of the expression of TGF-ß1 and the TGF-ß1 receptor-type II was conducted. Results: We observed that TGF-ß1 serum levels correlate with the genotype and are sex-related. TGF-ß1 serum levels were significantly elevated in patients compared to controls. Additionally, the T/T-genotype determined higher circulating levels of the cytokine. The same genotype determined the shorter median survival after surgery for the patients. The immunohistochemical analysis revealed a statistical tendency: cases expressing TGF-ß1 in the cytoplasm had elevated levels of the cytokine in the serum compared to the negative cases. Conclusions: Overall, our results indicate a negative effect of the T-allele on the predisposition and prognosis of brain malignancies, and the genetically determined higher TGF-ß1 serum levels might contribute to the worse prognosis and metastatic capacity of brain malignancies.

Protective Role of IL7A-197 A/G Heterozygosity in the Development and Severity of Colorectal Cancer in the Bulgarian Population.

Background: Interleukin (IL)-17A and IL-17F, expressed mainly by a novel subset of CD-positive (+) T-helper (Th) cells of the immune system, has been closely related to inflammatory conditions underlying colorectal cancer pathogenesis. Accordingly, we conducted a case-control study to investigate the association of common single nucleotide polymorphisms (SNP) in the IL17A and IL17F genes (rs2275913 and rs763780, respectively) with the susceptibility and severity of CRC patients from the Bulgarian population. Methods and Materials: 136 patients with histologically confirmed CRC diagnosis and 116 healthy individuals were recruited in the present study. Genotypes were determined by the restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) technique. Results: The IL17A heterozygous A/G-genotype was overrepresented among the control group (p = 0.003). Additionally, the carriers of the heterozygous A/G-genotype had a 2.39-fold lower risk for CRC compared to the G/G-genotype (OR = 0.418, p = 0.006). Our results also indicated that in the advanced CRC stages (III + IV) the heterozygous genotype (A/G) appeared to be less frequent (p = 0.024, χ2-test). Among the patients with detected distant metastases, the A/G-carriers were the smallest part (14.3%) compared to the homozygous genotypes A/A (42.9%) and G/G (42.8%), p = 0.006. There was no association of the studied IL17F rs763780 SNP with susceptibility and severity of CRC among the studied subjects, although the heterozygous C/T-carriers had shorter median survival compared to the T/T-carriers (p = 0.129). Conclusions: Our study finds a protective role of heterozygosity for the IL17A-197A/G SNP and negative effects of the A-allele on CRC progression.

Promoter polymorphisms in TGFB1 and IL10 genes influence tumor dendritic cells infiltration, development and prognosis of colorectal cancer.

BACKGROUND: Anti-inflammatory cytokines such as interleukin (IL)-10 and transforming growth factor (TGF)-ß1 have a complex role in the development of colorectal cancer (CRC). Dendritic cells (DCs) are the cellular component of the inflammatory microenvironment in the tumor and infiltration of tumors by DCs is associated with better prognosis and fewer metastases. METHODS: In the present study, we explored the role of two single nucleotide polymorphisms (SNPs) in the promoter regions of TGFB1 and IL10 genes and their associations with infiltrating DCs in CRC.A case-control study was designed. Genotyping was performed via the polymerase chain reaction-restriction fragment length polymorphism method and DC infiltration was determined immunohistochemically. RESULTS: For the TGFΒ1 -509C/T SNP, we found that the T allele was less frequent in patients than in controls (p = 0.031) and the TT-genotype had a 2.74-fold lower risk for CRC than the CC-genotype (odds ratio = 0.365, 95% confidence interval = 0.15-0.88, p = 0.015). Additionally, the TT carriers had the shortest median survival (14.4 months) (p = 0.045). The C-allele genotypes had a significantly longer survival compared to TT carriers (p = 0.018). The CC genotype was associated with a lower cellular density of CD11c in the invasive margin of the tumor (p = 0.033), whereas there was an opposite finding for CD83+ DCs (p = 0.037). Carriers of A-allele genotypes of the IL10 -1080A/G SNP had significantly lower CD83+ cells (p = 0.046) in the tumor invasive margin. CONCLUSIONS: The T-allele of the TGFB1 -509C/T SNP might be a protective factor for development of CRC, although, in the course of the disease, this variant allele might be associated with more unfavorable prognosis of the patients.

MMP12 -82 A>G Promoter Polymorphism in Bronchial Asthma in a Population of Central Bulgaria.

A characteristic feature of inflamed lungs in bronchial asthma (BA) is airway remodeling. Due to limited information on this topic in the literature, we aimed to explore the possible role of polymorphisms in the promoter region of the macrophage elastase gene MMP12 82A>G (rs2276109) as a predisposing factor for BA in an ethnic Bulgarian population. Using restriction fragment length polymorphism analysis of polymerase chain reaction-amplified fragments (PCR-RFLP), we performed genotype analysis of 58 patients and 119 control individuals. We found statistically significant differences in the distribution of genotypes (P = .008) and alleles (P = .004) between patients and nonaffected controls. In the dominant model, carriers of the G allele genotypes had 3.6-fold lower risk for BA, compared with those with the AA genotype, after adjustment for age and sex (odds ratio [OR], -0.277; 95% confidence interval [CI], .12-.65; P = .003). The results of our study suggest that the variant G allele of the MMP12 -82 A>G promoter polymorphism might be considered protective for development of BA in ethnic Bulgarian adults residing in central Bulgaria.

Association of IL-12Bpro polymorphism with tumor-infiltrating dendritic cells in colorectal cancer.

PURPOSE: Chronic inflammation is a key component in the development and progression of colorectal cancer (CRC). A notable hallmark of the inflammation process is the release of pro-inflammatory cytokines by infiltrating cells of the immune system. Defects in dendritic cells (DCs) recruitment, maturation and cytokine release are a hallmark of the CRC strategy to escape immune surveillance.The purpose of our study was to evaluate the possible role of IL-12B polymorphism in the promoter region of the IL-12B gene (rs17860508) as a genetic factor contributing to the risk for CRC development. Additionally, we aimed to evaluate the influence of this polymorphism on DCs infiltration in tumor microenvironment. METHODS: IL-12Bpro polymorphism was genotyped by Amplification Refractory Mutation System- Polymerase Chain Reaction (ARMS-PCR). Immunohistochemistry was performed for DCs infiltration. RESULTS: Statistically significant correlation between the expression of S100 and CD1a DCs and the 11- genotype of the studied polymorphism was found. No statistically significant difference in genotype distribution between cases and controls was observed (p=0.163). Analysis of the overall survival (OS) of genotyped patients revealed a tendency among the carriers of the 22-genotype to have shorter survival of 36 months versus the 11- and 12-cariers- 61 months (log rank, p=0.117). CONCLUSIONS: The IL-12Bpro polymorphism does not constitute a risk factor for CRC development. However, genotype-11 might have a complex role in the recruitment and maturation of DCs in tumor microenvironment.

The G allele of MMP12 -82 A > G promoter polymorphism as a protective factor for COPD in Bulgarian population.

Chronic inflammation and remodelling of the small airways are features related to chronic obstructive pulmonary disease (COPD). In the current study, we aimed to explore the possible role of MMP12 -82 A > G (rs2276109) promoter polymorphism in the development of COPD in a population from Bulgaria (167 patients with COPD and 119 control individuals). The genotype and allele distributions differed significantly between COPD patients and controls (p = .010 and p = .043, respectively, χ2 test). The genotypes containing at least one variant G allele (AA + GG) were more frequent in the control group than in patients (36.1% vs. 22.2%) determining 2.96-fold lower risk for COPD after adjustment for age, sex and smoking habits (OR = 0.338, 95%CI: 0.168-0.682, p = .002). Our results suggest that carriers of genotypes with at least one copy of minor G allele of rs2276109 might have lower risk for COPD development, with no marked effect on the lung function and severity of the disease.

Expression of E-Cadherin/Beta-Catenin in Epithelial Carcinomas of the Thyroid Gland.

BACKGROUND: The aberrant activation of Wnt signalling pathway may be a common denominator for the development of thyroid tumorigenesis. It was announced that the loss of E-cadherin rather than ß-catenin mutation represents a crucial event in determining the degree of differentiation of thyroid carcinomas. AIM: The aim of the study was to evaluate the expression of E-cadherin and ß-catenin in the thyroid cancer tissue and to correlate these data with some histological and clinical parameters of the tumours. MATERIAL AND METHODS: We investigated 112 patients, having thyroid tumours - papillary, follicular, anaplastic and oncocytic carcinomas immunohistochemically with antibodies against E-cadherin and ß-catenin. Survival analyses were done. RESULTS: E-cadherin expression was focally retained in the tumour cell membranes and the tumour cell cytoplasm of the papillary, follicular and oncocytic thyroid cancers, weather in anaplastic cancers it was almost lost (p = 0.0042, and p = 0.019, respectively, Fisher's Exact Test). The expression of ß-catenin in tumour cytoplasm and membrane in papillary cancers was higher as compared to that in the other tumours (p = 0.111, and p = 0.0104, respectively). CONCLUSION: Not surprisingly, the presence of aberrant expression of E-cadherin and ß-catenin in thyroid cancer has been associated with better patients' prognosis and better differentiated tumour histology.

Impact of TGF-ß1 expression and -509C>T polymorphism in the TGF-ß1 gene on the progression and survival of gastric cancer.

The aim of this study was to examine the expression of TGF-ß1 and TGF-ß receptor type II (RII) and the impact of the -509C>T single nucleotide polymorphism (SNP) in the gene in relation to clinicopathological factors in gastric cancer (GC). Using immunohistochemistry we investigated 43 patients with GC for expression of TGF-ß1 and TGF-ß-RII. Consequently, RFLP-PCR was performed to analyze the presence of -509C>T polymorphism in the TGF-ß1 gene. We found that 72.1% of GCs had cytoplasmic TGF-ß1 expression and 27.9% were negative. The TGF-ß1 receptor type II was expressed on tumor cell membranes in 58.1%. TGF-ß1 positivity in tumor cytoplasm correlated positively with TGF-ß1-RII expression in tumor cytoplasm in 67.4% of cases (2 = 8.02; p = 0.005). Also, the results showed that patients with low and moderate tumor differentiation had TGF-ß1-RII positivity in 53.3% and 81.8% resp. (2 = 6.58; p = 0,037). The analysis of genotype distribution of the -509C>T SNP in the promoter region of TGF-ß1 gene and clinical stage distribution revealed that among the 32 patients in III-IV clinical stage 53.1% were heterozygous (TC), 34.4% were homozygous for the C-allele and 12.5% were homozygous for the variant T-allele (2 = 3.31; p = 0.069). In conclusion the expression of TGF-ß1 was related to shorter survival time and rapid progression for the GC patients. Additionally, the variant T-allele of the studied polymorphism was associated with worse prognosis for GC patients.

Impact of HER2 codon 655 polymorphism and expression of HER2 and HER3 in non small cell lung cancer patients.

The aim of the study was to assess the expression and significance of HER2 and HER3, and Ile/Val single nucleotide polymorphism (SNP) of HER2 in lung cancer patients. Thirty seven cases of lung cancer were investigated immunohistochemically for HER2 and HER3 expression. PCR followed by restriction fragment length polymorphism (RFLP) was used to analyze the presence of HER-2 SNP at codon 655 in 20 samples. The results were compared with clinical and pathological parameters of investigated patients.We found that 100% of the cases were negative for HER2, 29.7% were with moderate or strong HER3 expression and 70.3% of the tumors-without or with low expression for HER3. Lymph node metastasis were found in 40% of HER3 positive cases (χ(2) = 4.752; p = 0.029). Moderately-differentiated tumors do not express neither of investigated markers (χ(2) = 6.719; p = 0.035). HER2 RFLP-PCR analysis showed genotype AG in five patients (25%) and the rest of 15 cases (75%) had АА (Ile/Ile) genotype. Patients with metastasis had genotype АА (Ile/Ile) in 80% and genotype AG (Ile/Val) in 20% (χ(2) = 2.857; p = 0.091).Our results indicate that SNP in HER2 codon 655 and investigation of HER2 and HER3 expression could be helpful to outline the prognosis for patients with lung adenocarcinoma.