Genomic Profiling of Stage II Colorectal Cancer Identifies Candidate Genes Associated with Recurrence-Free Survival, Tumor Location, and Differentiation Grade.

BACKGROUND: Identification of high-risk stage II colorectal cancer (CRC) patients, potential candidates for adjuvant chemotherapy, is challenging. Current clinical guidelines rely mainly on histopathological markers with relatively weak prognostic value. This motivates further search for prognostic markers. METHODS: This explorative study aimed to identify potential candidate gene mutations to facilitate differentiation between subgroups of patients with CRC stage II. Panel-based massive parallel sequencing was used to genetically characterize tumor tissues from 85 patients radically operated for CRC stage II, of which 12 developed recurrent cancer during follow-up. Genetic data was compared between patients with or without cancer recurrence, between tumors located in colon and in rectum, and for association with tumor differentiation grade. RESULTS: Genetic variation in ATM, C11ORF65 was associated with recurrence-free survival. Previous reports regarding the association between BRAF mutation and a higher age at diagnosis, and tumor location in colon were confirmed. APC, BRAF, or KRAS mutation was associated with tumor differentiation grade. Multiple correspondence analyses revealed no obvious clustering of patients with the studied clinical characteristics, indicating that the genetic signatures observed here were unique for each individual. CONCLUSIONS: Taken together, we have demonstrated the utility of panel-based massive parallel sequencing to explore the pathogenesis of CRC stage II. We have identified promising candidate gene mutations associated with cancer recurrence, tumor location, and differentiation grade in patients with CRC stage II, which merit further investigation.

Genetic polymorphism patterns suggest a genetic driven inflammatory response as pathogenesis in appendicitis.

PURPOSE: The pathogenesis of appendicitis is not well understood. Environmental factors are regarded most important, but epidemiologic findings suggest a role of inflammatory and genetic mechanisms. This study determines the association of single nucleotide polymorphisms (SNPs) of inflammatory genes with appendicitis. METHODS: As part of a larger prospective study on the diagnostic value of inflammatory variables in appendicitis, the genotype frequency of 28 polymorphisms in 26 inflammatory response genes from the appendicitis and control patients was analyzed in blood samples from 343 patients, 100 with appendicitis, and 243 with non-specific abdominal pain, using TaqMan SNP genotyping assays. RESULTS: Associations with appendicitis were found for SNPs IL-13 rs1800925 with odds ratio (OR) 6.02 (95% CI 1.52-23.78) for T/T versus C/C + T/T, for IL-17 rs2275913 with OR 2.38 (CI 1.24-4.57) for A/A vs G/G + GA, for CCL22 rs223888 with OR 0.12 (0.02-0.90), and for A/A vs G/G + GA. Signs of effect modification of age for the association with appendicitis were found for IL-13 rs1800925 and CTLA4 rs3087243. Stratified analysis showed difference in association with severity of disease for IL-17 rs2275913 and CD44 rs187115. CONCLUSIONS: The association of gene variants on risk of appendicitis and its severity suggest an etiologic role of genetically regulated inflammatory response. This may have implications for understanding the prognosis of untreated appendicitis as a possible self-limiting disorder and for understanding the inverse association of appendicitis with ulcerative colitis.

Possible Role and Therapeutic Target of PDGF-D Signalling in Colorectal Cancer.

Platelet-derived growth factor D (PDGF-D) has been shown to mediate cellular processes of importance in cancer progression. This study aimed to investigate the expression and putative involvement of PDGF-D signaling in colorectal carcinogenesis. PDGF-D was expressed in vascular endothelial cells in tumor and normal tissues. PDGF-D stimulation of cells altered genes of importance in carcinogenic processes. In addition, PDGF-D increased the proliferation rate while imatinib inhibited these effects. PDGF-D and its PDGF receptor beta (PDGFR-ß) are expressed in colorectal cancer and blockage of PDGF-D/PDGFR-ß signaling using tyrosine kinase inhibitors, such as imatinib, might be important in inhibiting tumor-promoting actions.

Altered PPARγ Coactivator-1 Alpha Expression in Abdominal Aortic Aneurysm: Possible Effects on Mitochondrial Biogenesis.

INTRODUCTION: Abdominal aortic aneurysm (AAA) is a complex and deadly vascular disorder. The pathogenesis of AAA includes destruction and phenotypic alterations of the vascular smooth muscle cells (VSMCs) and aortic tissues. PPARγ coactivator-1 alpha (PGC1α) regulates VSMC migration and matrix formation and is a major inducer of mitochondrial biogenesis and function, including oxidative metabolism. METHODS: Protein and gene expression of PGC1α and markers for mitochondria biogenesis and cell type-specificity were analysed in AAA aortas from humans and mice and compared against control aortas. RESULTS: Gene expression of PPARGC1A was decreased in human AAA and angiotensin (Ang) II-induced AAA in mice when compared to control vessels. However, high expression of PGC1α was detected in regions of neovascularisation in the adventitia layer. In contrast, the intima/media layer of AAA vessel exhibited defective mitochondrial biogenesis as indicated by low expression of PPARGC1A, VDAC, ATP synthase and citrate synthase. CONCLUSION: Our results suggest that mitochondrial biogenesis is impaired in AAA in synthetic SMCs in the media, with the exception of newly formed supporting vessels in the adventitia where the mitochondrial markers seem to be intact. To our knowledge, this is the first study investigating PGC1α and mitochondria biogenesis in AAA.

Prognostic significance of PLA2G4C gene polymorphism in patients with stage II colorectal cancer.

BACKGROUND: Phospholipase A2 Group IV C (PLA2G4C) catalyzes the release of certain fatty acids from phospholipids and plays a role in a range of physiological functions, such as remodeling of cell membranes and the production of prostaglandins. Furthermore, it has been proposed that PLA2G4C plays an important role in breast cancer cell chemotaxis. This study aimed to investigate the effect of a single nucleotide polymorphism (SNP) rs1549637 (T>A) of the PLA2G4C gene on the prognosis of colorectal cancer (CRC). MATERIAL AND METHODS: Whole blood DNA was extracted from 381 patients with CRC and 618 controls, and a TaqMan SNP genotyping assay was used to determine the distribution of the genotypes. Cancer-specific and disease-free survival was analyzed by Kaplan-Meier graphs and by uni- and multivariable Cox regression. RESULTS: The cancer-specific survival differed between the genotypes (p = 0.019) and the carriers of the A allele were associated with the highest risk of CRC death, with a hazard ratio (HR) of 1.72 [95% confidence interval (CI) 1.17-2.53, p = 0.006] compared with homozygous carriers of the T allele. This increased mortality in the carriers with the allele A was especially marked in stage II with an HR of 3.84 (95% CI 1.51-9.78, p = 0.005). CONCLUSION: The A allele in PLA2G4C SNP (rs1549637) is associated with a worse prognosis in patients with CRC, especially in stage II disease, and it could be a potential prognostic biomarker in the planning of individual adjuvant therapy in stage II patients.

CD93 gene polymorphism is associated with disseminated colorectal cancer.

PURPOSE: Cluster of differentiation 93 (CD93) is involved in apoptosis and inflammation and has a suggested role in angiogenesis, and all of which are involved in the development and dissemination of cancer. We evaluated the expression of CD93 and the association with two single nucleotide polymorphisms (SNPs), rs2749812 and rs2749817, as possible biomarkers in colorectal cancer (CRC). METHODS: Tissue levels and plasma levels of CD93 were measured using an enzyme-linked immunosorbent assay (ELISA). Expression of CD93 was determined by immunohistochemistry, western blot and gene expression analysis. Genotype frequencies were established for the SNPs by real-time polymerase chain reaction (PCR), and the association with tumour stage and survival was analysed. RESULTS: Total CD93 levels were 82% higher (P < 0.001) in tumours compared to matched normal tissues. Mean levels of soluble CD93 in plasma were 30% lower (P < 0.001) in the patients compared to the controls. The T/T genotype of SNP rs2749817 was more common in stage IV patients, with consequently higher risk of CRC death (T/T vs. C/C and C/T; hazard ratio (HR) = 1.73, 95% confidence interval (CI) = 1.11-2.67, P = 0.014), and was associated with a higher risk of CRC recurrence after radical operation (T/T vs. C/C and C/T; HR = 2.07, CI = 1.22-3.51, P = 0.007). CONCLUSIONS: We showed that the T/T genotype of SNP rs2749817 is associated with disseminated cancer at diagnosis and an increased recurrence rate after radical operation. Patients with this genotype may benefit from early identification.

Association of Clinicopathological Factors With MMP13 (rs2252070) Gene Polymorphism in Swedish Patients With Colorectal Cancer.

BACKGROUND/AIM: Matrix metalloproteinase 13 (MMP13) has been reported to be involved in tumor development and progression, including of colorectal cancer (CRC). This study aimed at evaluating whether the MMP13 rs2252070 gene polymorphism is associated with clinicopathological factors and its influence on long-term survival in Swedish patients with CRC. PATIENTS AND METHODS: A total of 723 patients with CRC were genotyped using TaqMan single nucleotide polymorphism assays based on polymerase chain reaction. RESULTS: Assessing clinicopathological factors, we demonstrated that having the G/G genotype for MMP13 rs2252070 was significantly associated with poor differentiation, higher serum level of carcinoembryonic antigen and higher lymph node status. Moreover, the presence of a G allele was significantly related to larger tumor size in rectal cancer but had a significantly protective role against mucinous cancer, perineural invasion and lymphovascular invasion. Kaplan-Meier analysis showed no difference between genotypes regarding cancer-specific survival. CONCLUSION: Our findings highlight the potential of MMP13 rs2252070 polymorphism as a useful predictor of poor differentiation, serum level of carcinoembryonic antigen, lymph node status, tumor size, mucinous cancer, perineural invasion and lymphovascular invasion in patients with CRC.

Clinicopathological and prognostic value of CD44 gene polymorphism (rs187115) in Swedish patients with colorectal cancer.

Cluster of differentiation (CD) 44 plays a crucial role in apoptosis, cell-cell interactions, angiogenesis, metastasis and proliferation. The aim of the present study was to examine the influence of CD44 gene polymorphism rs187115 on colorectal cancer (CRC) susceptibility and the association with various clinical features including long-term survival in Swedish patients with CRC. Genotypes were screened, using TaqMan single nucleotide polymorphism (SNP) assays based on polymerase chain reaction, in 612 CRC patients and 575 healthy controls.The carriers of G allele, genotypes (AG + GG), were found to be associated with an increased risk of CRC with an odds ratio (OR) of 1.35 (95% confidence interval (CI) = 1.01-1.81; p = 0.039) and found to be more common in patients with mucinous cancer compared with non-mucinous cancer, OR = 1.69 (95% CI = 1.02-2.80; p = 0.011). By using Kaplan-Meier analysis, the patients with genotype GG showed shorter cancer-specific and recurrence free survival with a hazard ratio (HR) of 1.25 (95% CI = 1.02-1.54; p = 0.036) and 1.52 (95% CI = 1.12-2.06; p = 0.007), respectively, in comparison with the carriers of A allele (AG + AA). The present findings demonstrated that the variant G allele of CD44 gene polymorphism rs187115 was related to risk for CRC and associated to mucinous cancer and predict worse prognosis in Swedish patients with CRC.

DNA promoter methylation status and protein expression of interleukin-8 in human colorectal adenocarcinomas.

BACKGROUND: Interleukin-8 (IL-8) also referred to as CXCL8, a member of the CXC chemokine family that attracts neutrophils and other leukocytes, has been associated with cancer. Angiogenesis is a prime regulator of tumour expansion and data support that IL-8 is a potent angiogenic factor. Epigenomic instability has been postulated to play a role for the development of multiple neoplasias including colorectal cancer (CRC). DNA methylation of cytosine residues in CpG dinucleotides leads to transcriptional silencing of associated genes. METHOD: In this study, we comparatively analysed the protein expression of IL-8 in plasma, tumour and paired normal tissue and methylation status of the IL-8 gene to evaluate its impact on CRC. RESULTS: Collectively, by using Luminex technology, we noted a significantly higher IL-8 level in cancer tissue compared to paired normal tissue and that CRC patients exhibit significantly higher plasma levels than healthy controls. Analysed by methylation-specific polymerase chain reaction, we detected IL-8 hypomethylation in 64% of the cancerous tissue cases but no hypomethylation was found in paired normal tissue. We noted that the CRC patients with IL-8 hypomethylation revealed a significant higher level of IL-8 protein in cancerous tissue, which tended to be associated with distant metastasis. We also observed that patients with distant metastasis showed a significantly higher plasma level of IL-8 in relation to patients without distant metastasis. CONCLUSION: Our results suggest that the predominance of high plasma levels of IL-8 in patients with distant metastasis in combination with the hypomethylation of the IL-8 promoter region might be a useful marker of the disease advancement.

Effects of diabetes type 2 and metformin treatment in Swedish patients with colorectal cancer.

The association between type 2 diabetes mellitus (DM) and colorectal cancer (CRC) has been thoroughly investigated and reports have demonstrated that the risk of CRC is increased in DM patients. The association between DM and the survival of patients with CRC is controversial. Evidence suggests that metformin with its anti-inflammatory effects is a protective factor against the development of CRC among DM patients and that metformin therapy is associated with a better prognosis in patients with DM. In our cohort, we did not find any associations between the presence of DM or metformin and cancer specific survival or any relation to plasma levels of a panel of 40 inflammatory factors and irisin. On the other hand, we identified that the insulin-like growth factor binding protein 7 single nucleotide polymorphism rs2041437 was associated with DM in CRC patients. The dominance of the T bearing genotypes in patients with DM was statistically significant (P = 0.038), with an odds ratio of 1.66 (95% confidence interval: 1.03-2.69).

Increased mortality in the A/A genotype of the SNP rs28372698 of interleukin 32.

One of the major causes of mortality in the western hemisphere is cardiovascular disease. Therefore, a variety of markers to identify those at risk are required. Interleukin-32 (IL-32) is a cytokine that is associated with inflammation. The aim of the current study was to investigate variations in single nucleotide polymorphisms (SNPs) of IL-32 and plasma expression, and their associations with mortality. A population of 486 elderly community-living persons were evaluated. The participants were followed for 7.1 years and underwent a clinical examination and blood sampling. SNP analyses of IL-32 rs28372698 using allelic discrimination and plasma measurement of IL-32, using ELISA, were performed. During the follow-up period, 140 (28.8%) all-cause and 87 (17.9%) cardiovascular deaths were registered. No significant difference between mortality and plasma concentration of IL-32 was observed. The A/A genotype group exhibited significantly higher all-cause mortality (P=0.036), and an almost two-fold increased risk in a multivariate Cox regression model for all-cause and cardiovascular mortality. A highly significant difference in all-cause and cardiovascular mortality between the A/A and the T/T groups was demonstrated (P=0.015 resp. P=0.014). In the present study, the cytokine IL-32 was demonstrated to have prognostic information, with an increased risk of all-cause and cardiovascular mortality for those with the A/A genotype rs28372698 of IL-32. The A/A genotype could therefore be regarded as a possible biomarker for mortality risk that may be used to offer optimized cardiovascular patient handling in the future. However, the present study sample was small, and the results should be regarded as hypothesis-generating.

Association of gene and protein expression and genetic polymorphism of CC chemokine ligand 4 in colorectal cancer.

BACKGROUND: Leukocytes, such as T cells and macrophages, play an important role in tumorigenesis. CC chemokine ligand (CCL) 4, which is produced by lymphocytes and macrophages, has been found to be expressed in the mucosa of the gastrointestinal tract and is a potent chemoattractant for various leukocytes. AIM: To examine CCL4 expression and its genetic polymorphism rs10491121 in patients with colorectal cancer (CRC) and evaluate their prognostic significance. METHODS: Luminex technology was used to determine CCL4 Levels in CRC tissue (n = 98), compared with paired normal tissue, and in plasma from patients with CRC (n = 103), compared with healthy controls (n = 97). Included patients had undergone surgical resection for primary colorectal adenocarcinomas between 1996 and 2019 at the Department of Surgery, Ryhov County Hospital, Jönköping, Sweden. Reverse transcription quantitative PCR was used to investigate the CCL4 gene expression in CRC tissue (n = 101). Paired normal tissue and TaqMan single nucleotide polymorphism assays were used for the CCL4 rs10491121 polymorphism in 610 CRC patients and 409 healthy controls. RESULTS: The CCL4 protein and messenger RNA expression levels were higher in CRC tissue than in normal paired tissue (90%, P < 0.001 and 45%, P < 0.05, respectively). CRC tissue from patients with localized disease had 2.8-fold higher protein expression levels than that from patients with disseminated disease. Low CCL4 protein expression levels in CRC tissue were associated with a 30% lower cancer-specific survival rate in patients (P < 0.01). The level of plasma CCL4 was 11% higher in CRC patients than in healthy controls (P < 0.05) and was positively correlated (r = 0.56, P < 0.01) with the CCL4 protein level in CRC tissue. The analysis of CCL4 gene polymorphism rs10491121 showed a difference (P < 0.05) between localized disease and disseminated disease in the right colon, with a dominance of allele A in localized disease. Moreover, the rate of the A allele was higher among CRC patients with mucinous cancer than among those with non-mucinous cancer. CONCLUSION: The present study indicates that the CRC tissue levels of CCL4 and CCL4 gene polymorphism rs10491121, particularly in the right colon, are associated with clinical outcome in CRC patients.

Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) Gene Polymorphism (rs3087243) Is Related to Risk and Survival in Patients With Colorectal Cancer.

BACKGROUND/AIM: Cytotoxic T-lymphocyte antigen-4 (CTLA-4), transiently expressed on T cells, plays a pivotal role in the negative feedback regulation of T-cell activation and proliferation. The aim of the present study was to examine the influence of CTLA-4 gene polymorphism rs3087243 on CRC susceptibility and long-term survival in Swedish patients with CRC. PATIENTS AND METHODS: Genotypes of 491 patients and 433 healthy controls were determined, using TaqMan single nucleotide polymorphism (SNP) assays based on polymerase chain reaction. RESULTS: Patients carrying allele A were found to be at a higher risk of CRC and this allele was found to be more common in patients with disseminated disease compared to localized disease in the right colon. Kaplan-Meier analysis of cancer-specific survival showed that carriers of allele A had the highest risk of CRC-related death. CONCLUSION: The SNP rs3087243 of the CTLA-4 gene was associated with CRC risk and, therefore, it could be a prognostic marker for Swedish patients with CRC.

Pigment epithelium-derived factor expression in colorectal cancer patients.

Pigment epithelium-derived factor (PEDF) is a potent inhibitor of angiogenesis and has been proposed to be a tumor suppressor in a variety of tumors. Limited reports exist of PEDF in colorectal cancer (CRC). We noted a 55% lower plasma level (p < .001) of PEDF in the CRC patient group (1.6 µg/mL) than in of a healthy control group (3.6 µg/mL). A single nucleotide polymorphism (rs1136287, T>C) was screened. In the control group, the CC genotype showed 30% lower PEDF plasma levels compared with the TT genotype (p < .01), whereas the CRC patients failed to show any association regarding these genotypes.

Association between adenomatosis polyposis coli functional status and microsomal prostaglandin E synthase-1 expression in colorectal cancer.

Bioactive metabolites downstream of cyclooxygenase-2 (COX-2) generated prostaglandin H(2) (PGH(2)), in particular prostaglandin E(2) (PGE(2)), are thought to play critical roles during the development of colorectal tumors. Previous reports reveal that defects of the tumor suppressor adenomatosis polyposis coli (APC) contribute to COX-2 upregulation in colon tumor cells. We investigated whether a similar relation was present between APC functional status and the expression of microsomal prostaglandin E synthase-1 (mPGES-1), which acts downstream of COX-2 and catalyses the terminal conversion of PGH(2) into PGE(2). Surprisingly, mPGES-1 mRNA and protein levels were upregulated upon induction of a wild type-APC carrying vector in HT29 colon cancer cells, and downregulated following siRNA silencing of APC in HCT-116 cells. mPGES-1 was overall enhanced in human colorectal tumor specimens versus corresponding non-tumor mucosa and, in accordance with data on HT29 and HCT116 cells, higher levels of mPGES-1 were observed among tumors carrying wild type versus mutant APC. RNAi silencing of beta-catenin and luciferase assays regarding the mPGES-1 promoter region did not reveal a role for APC or beta-catenin/Tcf in controlling mPGES-1 gene transcription. However, RNA degradation assays in HT29 cells revealed a suppressed degradation of mPGES-1 in the presence of wild type APC, implying that mPGES-1 mRNA is stabilized in the APC wild type state. Collectively, we demonstrate a novel association between APC functional status and mPGES-1 expression in colorectal tumor cells, being most likely related to reduced mPGES-1 mRNA degradation rate in the APC wild type state.

Decreased expression of the chemokine CCL21 in human colorectal adenocarcinomas.

Recent studies have revealed participation of chemokines in cancer by regulating leukocyte movement to modify local immunoresponse. The chemokine CCL21 has been identified to play a pivotal role in homing and localization of immune cells to lymphoid tissue and into organ of non-lymphoid origin. In the cancer biology CCL21 seems to have multifaceted roles. CCL21 attracts CCR7 bearing cells especially T and dendritic cells but also various cancer cells. Besides the antitumour role as leukocyte recruiting, CCL21 has been shown to facilitate dendritic cell functions and to exert an angiostatic effect. To gain insight into the possible influence of CCL21 on colorectal cancer (CRC) we determined whether the CCL21 is altered in CRC tissue. Collectively, by using ELISA we noted a significant lower CCL21 level in cancer tissue compared with paired normal tissue. Patients with a tumour localized in the rectum revealed significantly lower level of CCL21 than patients with a tumour localized in the colon both compared with paired normal tissue. We used immunohistochemistry and found heterogeneous immunoreactivity predominantly within areas of stromal cells mainly in macrophages. We also used a TaqMan system to investigate two single-nucleotide polymorphisms rs 11574915 and rs 2812377 with supposed effect on CRC. No significant difference was observed between CRC and control subjects regarding genotype and allelic distributions or associations to clinical characteristics or CCL21 tissue levels. Our study implied that lower level of CCL21 in CRC tissue supports the idea that cancer is related to immunodeficiency probably depending on regulatory factors produced by tumour cells and that the different levels of CCL21 in rectum and colon may reflect divergent mechanisms in colorectal carcinogenesis. Further studies are needed to clarify whether the CCL21 level has an impact on CRC progression and survival rate.

Genetic Variants of the IL2 Gene Related to Risk and Survival in Patients With Colorectal Cancer.

BACKGROUND: Interleukin 2 (IL2) is a significant factor activating T-cell-mediated immune response by stimulation of natural killer cells, T-cells and in development of regulatory T (Treg) cells. Recent studies have that IL2 participates in cancer development by modifying the local immune response. Based on the suggested role of the single nucleotide polymorphisms (SNPs) rs2069762, rs6822844 and rs11938795 of IL2 in the pathogenesis of certain diseases, the relationship of these SNPs with clinicopathological variables and their possible implication for prognosis and disease outcome were evaluated in a cohort of Swedish patients with colorectal cancer (CRC). MATERIALS AND METHODS: TaqMan SNP genotype assays based on polymerase chain reaction were used for analysis of the IL2 SNPs in 467 patients with CRC and 467 healthy controls. Expression analysis of IL2 in plasma and CRC tissue was also performed. RESULTS: The allelic variants T in rs11938795 and G in rs6822844 were significantly associated with a higher risk of CRC. Kaplan-Meier analysis showed that cancer-specific survival was worse for individuals with C allele for rs2069762 with stage II CRC and with T allele for rs6822844 with stage III CRC. CONCLUSION: SNPs rs2069762, rs6822844 and rs11938795 of the IL2 gene may be helpful as prognostic biomarkers in the follow-up and management of the patients.

Resistin in human colorectal cancer: increased expression independently of resistin promoter -420C > G genotype.

A single nucleotide polymorphism (SNP) -420C > G of the resistin gene was screened in 248 colorectal cancer (CRC) patients and 256 controls. No significant difference in genotype distribution was found. However, we found an upregulation in 92% of the samples in the levels of resistin protein in cancer tissue (n = 83). Immunohistochemical analysis revealed heterogenous staining of resistin predominantly in the cancer tissue. Further, resistin induced secretion of MMP-2 and MMP-9 from monocytes. The results of this study suggest that resistin may play a partial role in CRC but that the -420C > G resistin polymorphism is not a potential genetic susceptibility factor.

Polymorphism in MHC class II transactivator gene is not associated with susceptibility to colorectal cancer in Swedish patients.

BACKGROUND: Reduced expression of major histocompatibility complex class II (MHC-II) genes in colorectal cancer (CRC) has been reported. MHC-II transactivator (CIITA), encoded by the MHC2TA gene, is considered to be the master regulator for MHC-II gene expression. A functional single nucleotide polymorphism (SNP) -168A-->G in the promoter region of the MHC2TA gene is suggested to have an influence on different autoimmune diseases. PATIENTS AND METHODS: Our study was performed to evaluate the association between the -168A-->G MHC2TA gene variant in patients with CRC versus a control group. Using the TaqMan system, this SNP was screened in 248 CRC patients and 256 controls. RESULTS: No significant difference in genotype distribution or in allelic frequencies was found between the two groups, nor any association with clinical characteristics. CONCLUSION: The results of this study suggest that -168A-->G polymorphism of the MHC2TA gene is not associated with susceptibility to CRC.

Protein Expression and Genetic Variation of IL32 and Association with Colorectal Cancer in Swedish Patients.

BACKGROUND: Interleukin 32 (IL32) is an intracellular pluripotent cytokine produced by epithelial cells, monocytes, T-lymphocytes and natural killer cells and seems to be involved in the pathogenesis of cancer and inflammatory diseases. Our purpose was to assess the role of protein expression and genetic polymorphisms of IL32 in colorectal cancer (CRC) susceptibility. MATERIALS AND METHODS: To gain insight into clinical significance of IL32 in Swedish patients with CRC, using enzyme-linked immunosorbent assay, we determined whether IL32 protein level is altered in CRC tissue (n=75) compared with paired normal tissue and in plasma from patients with CRC (n=94) compared with controls (n=81). The expression of IL32 protein was confirmed by immunohistochemistry (n=73). We used Luminex technology to investigate protein levels of the cytokines IL6, tumor necrosis factor-α (TNFα) and vascular endothelial growth factor (VEGF) to relate these to IL32 levels in CRC tissue. Three single nucleotide polymorphisms (SNPs) (rs28372698, rs12934561, rs4786370) of the IL32 gene have been proposed as modifiers for different diseases. The present study evaluated the susceptibility of patients possessing these SNPs to CRC. Using TaqMan SNP genotyping assays, these SNPs were screened in Swedish patients with CRC (n=465) and healthy controls (n=331). RESULTS: We found no significant differences in the genotypic frequencies between the patients and healthy controls and no relation to survival for any of the SNPs. However, the SNP rs12934561 was statisticalLY significant associated with older patients. IL32 protein was up-regulated in CRC tissue and related to IL6, TNFα, and VEGF, and seems to be modulated by SNP rs28372698. The IL32 protein level in CRC tissue also reflects both disseminated disease and location. CONCLUSION: Our results suggest that altered IL32 protein concentrations in CRC tissue and genotypic variants of IL32 are related to disseminated CRC.